Circular knitting machine



c. H. WA INWRIGHT CIRCULAR KNITTI NG MACHINE June 9, 1942.-

Filed June 24, 1941 Patented June 9, 1942 v UNITED STATES PAT EN T OFFICE CIRCULAR KNITTING MACHINE Carlyle HerbertfWainwright, Leicester, England; assignor to i The Bentley Engineering Company Limited; Leicester, England, a British company Application. June 24, 1941, Serial-No. 399,516

Claims,

This invention consists of improvements in or relating to circular knitting machines and is particularly concerned'with those devices knownas pickers which are empl'oyedin knitting machines to move a needle, or more than one needle, from'one position to another in the. trick or groove in which the needle or each needle is situated. For instance, in the knitting of heel and toe pouches, the necessary narrowing and widening of the knitted fabric is produced by the shifting of one needle or two needles simultaneously from the control of one cam track to the control of another.

One form of such device which is in common use (and on which the present invention constitutes an improvement) consists (in the case of a machine having a moving needle cylinder and a stationary cam-box of a lever or'arm pivoted outside the needle cylinder on a stationary part of the machine or on a bracket attached- When in to a stationary part of the machine; its operative position the arm extends more or less radially of the needle cylinder with its inner' or free end close to the cylinder within range of the butts of the needle sliders as the sliders move round with the cylinder. The arm is piv-' oted about a vertical axis and also about a horizontal axis so that the end close to the cylinder can move in any direction on its own sphere, but the direction in which it does move is determined by a cam with which thearm makes con-' tact either at some point between the pivot and the end close to the cylinder or on an extension of the arm on the side of the pivot away from the cylinder. At its free end the arm is formed with a horizontal portion and a vertical wall to engage the slider butts. Assuming the picker is to lower two needlesineach direction of each reciprocation of the needle cylinder during the widening operation on a heel or toe pouch, the horizontal portion and vertical portion will take the form of a letter T and the mode of operation will be as follows:

When the butt of the first needle slider to besliders until, owing to the mutuallydivergent paths of the picker end andjthe butts, the butts become out of reach of the pickers. The butts will, by this time, be lowered to a position where they are out of range of, the cam track which was previously controlling them.

Pickers of the known type described operate satisfactorily up to a point, but butt breakages and miss-picking do occur and they become serious faults at high speeds. Butt breakages have been discovered to be caused most usually by friction between the arm and the cam, making the action hard; and miss-picking has been caused by sluggish return of the arm to its receiving position, also due to friction between the arm and cam. An increase in the strength of the spring which returns the arm to its receiving position, while tending to relieve the latter fault, will only aggravate the former;

It is the object of the present invention to overcome both these difficulties.

The present invention comprises, in or for a circular knitting machine, the combination of a picker movable about two axes transverse to one another, means which serves to rock the picker about one axis and which comprises two arms inclined towards one another to embrace the picker, resilient means to permit and to' control movement of the picker about the other axis, and means to move the arms for the purpose of rocking the picker. Preferably, the movement imparted to the arms rocks the picker about an axis that will move its operative end (i. e. the end which will engage'a needle slider or aneedle) lengthwise of the needles.

Conveniently, the arms are interconnected by resilient means to maintain them both resiliently in engagement with the picker and in one form the arms embrace the picker on that side of its pivot remote from the needle bed.

A modification. of the invention comprises the combination with a picker pivoted about two axes transverse to one another of a plunger endwise movable along one of these axes or in a line parallel therewith and a coupling between the plunger and the outer end of the pickerwhich can transmit thrust to the picker in a line along or parallel with one of the axes and allows resilient movement of the picker around the same axis,

Preferably, the picker lever is pivoted about vertical and horizontal axes respectively, the plunger isvertically movable and the coupling transmits'the thrust in a vertical direction to the picker and'permits resilient movement of the picker around that vertical axis;

Thus according to this invention the coupling between said plunger and the outer end of the picker lever may comprise a pivoted member arranged to transmit thrust from said plunger to said picker in a vertical direction and controlled by resilient means to allow movement of said picker about its vertical axis. The resilient means may be arranged to bring the coupling member (and the outer end of the picker lever) back to normal position after the picker has completed an operation and passed out of contact with the needles.

A preferred form of this invention comprises in a circular knitting machine the combination with a picker lever pivoted about a vertical axis and also about a horizontal axis, of a vertically movable plunger and a coupling between the plunger and the outer end of the picker lever comprising a bar fixed to the plunger at rightangles to its axis and two arms pivoted to the opposite ends of said bar,'recessed on their upper inner faces to embrace said picker end in all positions, and a spring connecting said two arms so as to restore them to their normal position when the picker lever has completed an operation.

The picker lever may itself be spring controlled to assist the return of the picker lever to its central or receiving position in relation to the needle cylinder and to assist the picker lever (and associated parts) to return to inoperative position when the plunger is free from axial thrust.

In order that the invention may be more clearly understood a preferred example will now. be described in detail with the aid of the accompanying drawing, in which Figure 1 is a side elevation of a picker mecha nism constructed according to the present invention, and

Figure 2 is an elevation looking from the right in Figure 1.

Like reference numerals indicate like parts in both figures of the drawing.

The picker mechanism is intended to be applied to a circular knitting machine having a moving needle cylinder and a stationary cam box. A bracket fixed to a stationary part of the machine outside the needle cylinder has a vertical cylindrical hole in which can rotate the vertical stem II of a support l2 for the picker lever I3. The picker lever is pivoted on a horizontal pin M in the support I 2. The inner end of the picker lever has a recess for the reception of the needle butts on each side, each recess being formed by a horizontal portion and a vertical wall l6 conveniently of T-form in section. It will be realised quite clearly that the picker lever 53 can move freely in its vertical plane about pin I4 and can also oscillate around the axis of vertical stem H so that the picker is movable as heretofore in any direction in its own sphere.

In another cylindrical hole is located a cylindrical portion [1 of a plunger l7, lb of which the part I 8 is formed as a head having a flat face which bears at l9 against a corresponding flat face of bracket Ill. The bearing of these two flat faces prevents rotation of the plunger around the axis of the cylindrical portion H. The object of the plunger is to actuate the picker and in particular to impart vertical movement to the rear or outer end thereof. The plunger is subject to vertical movements at appropriate times by mechanism which forms no part of the present invention but which may conveniently comprise a lifting cam or lever which engages with the under side 20 of the cylindrical part I! of the plunger.

On the outer side of the plunger head I 8 is fixed by means of screw 32 a horizontal bar 2| projecting a short distance on each side of the axis of plunger I7, l8. At opposite ends of bar 2| there are pivoted, on horizontal pins 22, 23, arms 24 and 25 respectively the function of which is to act jointly as a coupling to the outer end of picker lever l3. These two arms 24 and 25 lie in a vertical plane and their upper ends are notched or cut away at adjacent corners, each notch being formed with one wall that is more or less lengthwise of the arm and another wall that is transverse thereto. The notches are such that in the first place they can overlap as shown clearly in Figure 2 to embrace between them the outer end 25 of the picker l3 and the opposed faces of the arms are rebated so as to overlie one another each with half its thickness as clearly shown in Figure 1. When in engagement with the end 26 of the picker the two arms are conveniently inclined endwise like the arms of letter A as seen best in Figure 2 and a convenient form of notch for the end of each lever is a rightangled recess cut inwardly from the outer end of the arm as shown. The two arms are coupled together by a spring 21 which performs the triple function of (a) holding the notched portions of the arms in contact with the outer end of the picker arm, (b) allowing resilient lateral movement of the end 26 of the picker and of the arms themselves, and (c) restoring the picker end 26 and the arms to their normal mid position, illustrated in the drawings after the picker is freed from the needles.

When the plunger l7, I8 is in its lowest position, the inner end l5, Id of the picker is raised into an inoperative position; but when plunger l1, I8 is raised this moves upwardly, the outer end 26 of the picker thus lowering its inner end in the vertical direction to a position ready for picking. Lateral movement due to the rotation of the needle cylinder and the engagement of the butts of the needles or needle jacks is accommodated by the form of coupling comprising arms 24, 25 and spring 2'! already described.

A fine adjustment for the exact setting of the operative position of the picker may be provided and in the example shown a pointed screw 28 acts by means of its pointed extremity as a stop to engage the lower edge of a hole 29 formed in the plunger part II. Thescrew 28 is located in its adjusted position by means of a lock-nut 38.

The picker lever l3 itself is conveniently controlled by resilient means such as a spring or springs 3| compressed between the picker arm and its support l2 on the cylinder side of pin M. A spring such as 3| assists in returning the picker to its central or receiving position and plunger I1, !8 to its inoperative position, and furthermore it also assists spring 21 in centralising arms 24 and 25 when the plunger is 'no longer under thrust and the picker itself is free from engagement with the needles or needle jacks.

I claim:

1. In or for a circular knitting machine, the combination of a picker movable about two axes transverse to one another, means which serves to rock the picker about one axis and which comprises two arms inclined towards one another to embrace the picker, resilient means to permit and to control movement of the picker about the other axis and means to impart movement to the arms which movement is transmitted by the arms to the picker to rock the latter.

2. In or for a circular knitting machine, the combination according to claim 1 in which movement imparted to the inclined arms is such as to rock the picker about an axis that will move its operative end lengthwise of the needles.

3. In or for a circular knitting machine the combination of a picker pivoted about two axes transverse to one another, a plunger movable endwise in a direction lengthwise of one of these axes, a coupling between the plunger and the outer end of the picker comprising a bar fixed to the plunger and at right angles to its axis and two arms which are pivoted to the opposite ends of said bar are recessed at their upper inner faces to embrace the said picker in all positions, and a spring connecting the said two arms to restore them to their normal position after they have been moved therefrom by movement of the picker and means for moving the plunger.

4. In or for a circular knitting machine, the combination of a picker movable about two axes transverse to one another, a member movabl in a direction lengthwise of one of these axes, means comprising a resilient coupling between the said member and the picker through which thrust is transmitted to the latter and which will permit resilient movement of the picker around the same axis, and spring means controlling return of the picker to its central or receiving position in relation to the needle cylinder after it has been displaced from that position and is returned to its inoperative position.

5. In or for a circular knitting machine, a device comprising in combination a picker lever pivoted intermediate its ends in a support, a bearing for said support in which the latter is rotatable about an axis at right angles to the pivotal axis of the picker, a plunger endwise movable in a guide in a direction parallel with the axis about which the picker support rotates, a bar secured to and extending on both sides of the plunger at right angles to the axis of the latter, two arms pivoted at their lower ends at or near the extremities of the bar and convergent upwardly, the said arms having recessed upper extremities which are overlapped to embrace between them the outer extremity of the picker lever, a tension spring interconnecting the two arms at positions between their extremities for the purpose of causing the arms resiliently to embrace the picker end in all positions.

6. In or for a circular knitting machine, the subject matter of claim 5 having in addition a compression spring received in the picker support to engage the picker between its pivotal axis and its operative extremity, for the purpose described.

7. In or for a circular knitting machine, the combination according to claim 5 in which the plunger is formed with a recess and is combined with an adjustable stop which enters the recess to an adjustable degree to limit movement of the plunger at least in an upward direction.

8. In or for a circular knitting machine according to claim 5 and in addition a compression spring received in the picker support to engage the icker between its pivotal axis and its operative extremity, a recess in the plunger and an adjustable stop in the plunger support to enter the recess to an adjustable degree to limit movement of the plunger at least in an upward direction.

9. In or for a circular knitting machine, the combination of a picker movable about two axes transverse to one another, a member movable in a direction lengthwise of one of these axes and means comprising a resilient coupling between said member and the picker through which coupling thrust is transmitted to the picker along said line and will permit resilient movement of the picker around the same axis.

10. In or for a circular knitting machine, the combination according to claim 9 in which a plunger constitutes the movable member and is movable in an axial direction for the purpose of imparting the requisite movement to the picker.

CARLYLE HERBERT WAINWRIGHT. 

